Winter Storm Dec 11th - Dec 12th 2010

Winter Storm from Saturday December 11th at 7 PM through Sunday December 12th at 7 PM

This was a two-part storm. The first part of the event was caused by warm air over spreading across colder air. Rain developed over Western Lower Michigan on Saturday evening around 7 PM (Image 1). The precipitation spread quickly across the remainder of the state by 9 PM. When the precipitation reached areas north of Interstate 96, it turned to snow. Temperatures were in the mid to upper 30s south of Interstate 96, while they were in the lower to mid 30s north. Over time, the rain to snow line slipped slowly south. By midnight the precipitation was mostly snow north of Interstate 94 (Image 2).

Areas north of Route 10 had moderate to heavy snow for a good portion of the overnight hours. This area saw nearly a foot of snow by Sunday morning. This included Reed City, in southern Osceola County, where 9 inches of snow was measured by 7 AM Sunday (Image 3). Cadillac had a foot of snow by then. Meanwhile, just south of Route 10, 4 to 6 inches of snow was reported. Further south, the ground and surface air temperatures were a degree or two too warm for the snow to accumulate. In locations around Grand Rapids accumulations of around an inch occurred, even though most of the precipitation actually fell as snow.

In the second part of the storm, the primary surface system had moved to western Lake Erie by 10 AM Sunday morning. The radar image just prior to that (Image 4) showed little if any precipitation was falling over western Lower Michigan. Light snow was falling over the remainder of the state. Around 11 AM, arctic air was finally pulled far enough south to impact Southwest Lower Michigan. It was at this time the second phase kicked in and the snow began to fall moderately from Grand Rapids eastward to Lansing (Image 5). Winds increased to 20 to 30 mph with some gusts as high as 60 mph (as reported at Ludington State Park at 4:40 PM). The snow continued to fall from Grand Rapids east to Lansing through much of Sunday afternoon. Roads become very slippery as temperatures fell from the lower 30s around noon to the upper teens by late afternoon. Interstate 96 and 94 were closed at times due to accidents. Eight deaths due to accidents occurred across the state during the storm. By 6:30 PM Sunday, the moderate to heavy snow had weakened considerably (Image 6).

Besides the hazardous travel, numerous power outages were reported as power lines were blown down by the strong wind. The snowfall plot from 7 AM Monday, December 13th, 2010 showed 4 to 6 inches fell over the Lansing area, with 2 to 4 inches between Grand Rapids and Lansing. Lesser amounts occurred to the southwest of Grand Rapids (Image 7).

The storm total snowfall ranged from an inch or two over sections southwest of Grand Rapids to around 5 inches in the Lansing area, to as much as 10 to 15 inches over parts of northern Lake, Oceola and Clare Counties. Most of the heavy snow north of Route 10 fell with part one of the storm. The 3 to 5 inches from east of Grand Rapids to Lansing mostly fell during Sunday afternoon into early Sunday evening.

The storm total snowfall from 7 PM Saturday December 11th through Sunday December 12 at 7:00 PM